Rapid development of display technology originates in life need. Today, display devices have been widely applied to various equipment, such as televisions, computer monitors, smart phones, tablet computers, etc, for showing visual images dynamically. In addition, touch screen technology has been used to electronic devices for achieving intuitive two-way communication these days. However, frequent use of a touch screen may cause abrasion of the screen surface. To solve this problem, screen protectors are usually employed to isolate the touch screen so as to prevent the abrasion due to finger contact. Thus, how to apply a screen protector to a visual image zone in a rapid and accurate manner has become a topic that deserves our attention and investigation.
Generally, a conventional screen protector is provided with a backing sheet for isolating the adhesive on its film body. The backing sheet remains until the screen protector is applied to a visual image zone of a device. Usually, the conventional screen protector is installed in a manual way. After the backing sheet is peeled off by grasping its one end, the user may gradually attach the film body to the entire visual image zone with his or her naked eyes monitoring the attachment process. If careless, bubbles may be trapped between the film body and the visual image zone or the film body may not be aligned with the visual image zone properly. Since electronic devices, such as smart phones, tablet computers, desktop computers, and small televisions, have a need to be installed with a screen protector, for convenience of illustration, the forgoing devices containing visual image zones are referred to as “screen-mounted devices”, and the visual image zones are term as “screen displays”.
For reducing the non-alignment problem and bubbles trapped in a screen protector, some vendor proposed a method for applying a screen protector to a screen-mounted device, wherein the screen protector, including a film body and a backing sheet, is first aligned with a screen-mounted device, and then the screen protector is fixed to the one side of the screen-mounted device using a tape, after which the backing sheet can be removed to have the film body of the screen protector attached to the display screen of the screen-mounted device. However, this method may consume a lot of time, and cannot avoid relative movement between the screen protector and the screen-mounted device during the process of removing the backing sheet. Besides, during the process of attaching the film body to the screen-mounted device, the user should repeatedly squeeze the film body to prevent bubble trapped under the film body.
To facilitate the operation of installing a screen protector, some vender provides an application device to assist the installation. The application device employs a fixed seat in cooperation with a movable holder, and a screen protector with an extended backing sheet. In operation, a screen-mounted device is placed on the movable holder, and one end of the extended backing sheet is fixed to the seat. Next, the user may pull a knob to have the movable holder retracted, during which the backing sheet can be gradually removed from the film body of the screen protector, and the screen-mounted device is transported deep into the fixed seat, where the pressing element of the fixed seat can squeeze the film body, so that the film body can be attached to the display screen of the screen-mounted device. Although the application device allows a user to conduct an attachment process more easily, the attachment process is completed in the deep of the fixed seat. Under this circumstance, the user cannot monitor the details of the attachment process immediately; therefore, the screen protector may be not aligned with the screen-mounted device properly. Besides, the application device is very heavy and thus has difficulty in storage or transportation, the operation is laborious, and the use of the extended backing sheet for the screen protector is uneconomical and not environmentally friendly.
In view of the foregoing, there is a need to provide an improved application device that can be operated more easily to conduct an attachment process without compromising the accuracy of aligning a screen protector with a screen-mounted device, and is simple in structure to reduce the weight and to lower the manufacturing cost. With the improved application device, screen protectors can be applied onto screen-mounted devices more properly, and the working efficiency can be increased.